Projection apparatus

Abstract

A projection apparatus including an illumination system, a reflective light valve, an imaging system, a loop heat pipe and a heat sink is provided. The illumination system is capable of providing a light beam and the reflective light valve is disposed on the transmission path of the light beam to convert the light beam into an image. The loop heat pipe includes an evaporator, a wick structure, at least a connecting pipe and working fluid. The evaporator includes a fluid backflow end and a vapor exhaust end, and the outer surface of the evaporator is connected to the reflective light valve. A wick structure is disposed inside the evaporator and connected with the fluid backflow end. The connecting pipe is connected between the fluid backflow end and the vapor exhaust end. The working fluid is located in the connecting pipe and the wick structure.

What is claimed is: 
     
         1 . A projection apparatus, comprising:
 an illumination system for providing an illumination light beam;   a reflective light valve disposed on a transmission path of the illumination light beam to convert the illumination light beam into an image light beam;   an imaging system disposed on a transmission path of the image light beam;   a loop heat pipe including:
 an evaporator section having a fluid backflow end and a vapor exhaust end, wherein an outer surface of the evaporator section is in contact with the reflective light valve; 
 a wick structure disposed inside the evaporator section and connected to the fluid backflow end; 
 at least a connecting pipe having a condenser section, wherein the connecting pipe is connected to the fluid backflow end and the vapor exhaust end; and 
 a working fluid located in the connecting pipe and the wick structure; and 
   a heat sink contacted to the condenser section of the connecting pipe.   
     
     
         2 . A projection apparatus as in the  claim 1 , wherein the reflective light valve comprises a digital micro-mirror device (DMD) or a liquid crystal device of silicon (LCOS). 
     
     
         3 . The projector apparatus as in the  claim 1 , wherein the connecting pipe has a plurality of turnings. 
     
     
         4 . The projector apparatus as in the  claim 1 , wherein the connecting pipe comprises a plurality of sub-pipes communicated with each other. 
     
     
         5 . The projector apparatus as in the  claim 1 , wherein the connecting pipe comprises a plurality of sub-pipes not communicated with each other. 
     
     
         6 . The projector apparatus as in the  claim 1 , wherein the connecting pipe comprises copper pipes or aluminum pipes. 
     
     
         7 . The projector apparatus as in the  claim 1 , wherein the connecting pipe comprises a plurality of rigid pipes and at least a flexible pipe connected to two of the rigid pipes. 
     
     
         8 . The projector apparatus according to  claim 1 , wherein the evaporation temperature of the working fluid is between 20° C. to 60° C. 
     
     
         9 . The projector apparatus according to  claim 1 , wherein the working fluid comprises water. 
     
     
         10 . The projector apparatus according to  claim 1 , wherein a material of the evaporator section comprises copper or aluminum. 
     
     
         11 . The projector apparatus according to  claim 1 , wherein the evaporator section has an inner space and the working fluid permeated in the wick structure is evaporated so as to flow from the inner space to the vapor exhaust end. 
     
     
         12 . The projector apparatus according to  claim 1 , wherein the evaporator section has a heat dissipation fin located on an outer surface thereof. 
     
     
         13 . The projector apparatus as in the  claim 1 , wherein the heat sink comprises a plurality of heat dissipation fins or a heat dissipation plate. 
     
     
         14 . The projector apparatus as in the  claim 1 , further comprising a thermoelectric cooling device disposed between the reflective light valve and the loop heat pipe. 
     
     
         15 . The projector apparatus as in the  claim 1 , further comprising a cooling fan for cooling the heat sink.